Interface Trap Effects on the Hot-Carrier Induced Degradation of MOSFETs during Dynamic Stress

Foundry and hardened n-channel MOSFETs were stressed with dynamic AC pulses and with static DC voltages. The pre-radiation hot-carrier induced degradation is identical for devices from both processes when subjected to static stress, but when subjected to dynamic stress, the degradation is much more severe for the hardened devices. The data suggest that the degradation is strongly influenced by the pulse structure and it is proposed that the initial density of interface traps may be responsible for the enhancement in degradation exhibited by the hardened devices following dynamic stress.